rm/rm.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 static const char copyright[] =
  36 "@(#) Copyright (c) 1990, 1993, 1994\n\
  37         The Regents of the University of California.  All rights reserved.\n";
  38 #endif /* not lint */
  39
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  43 #else
  44 static const char rcsid[] =
  45   "$FreeBSD: src/bin/rm/rm.c,v 1.33 2001/06/13 15:01:25 ru Exp $";
  46 #endif
  47 #endif /* not lint */
  48
  49 #include <sys/stat.h>
  50 #include <sys/param.h>
  51 #include <sys/mount.h>
  52
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #include <fts.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60 #include <sysexits.h>
  61 #include <unistd.h>
  62
  63 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  64 uid_t uid;
  65
  66 int     check __P((char *, char *, struct stat *));
  67 void    checkdot __P((char **));
  68 void    rm_file __P((char **));
  69 void    rm_overwrite __P((char *, struct stat *));
  70 void    rm_tree __P((char **));
  71 void    usage __P((void));
  72
  73 #ifdef __APPLE__
  74 /* We lack fflagstostr(), but ls has a flags_to_string function
  75  * that does the same thing.  So...  We really use that.
  76  */
  77 char * flags_to_string(u_long, char *);
  78 #define fflagstostr(x) flags_to_string((x), NULL)
  79
  80 /* We're missing this prototype */
  81 int undelete __P((char *));
  82 #endif
  83
  84 /*
  85  * rm --
  86  *      This rm is different from historic rm's, but is expected to match
  87  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  88  *      has two specific effects now, ignore non-existent files and force
  89  *      file removal.
  90  */
  91 int
  92 main(argc, argv)
  93         int argc;
  94         char *argv[];
  95 {
  96         int ch, rflag;
  97         char *p;
  98
  99         /*
 100          * Test for the special case where the utility is called as
 101          * "unlink", for which the functionality provided is greatly
 102          * simplified.
 103          */
 104         if ((p = rindex(argv[0], '/')) == NULL)
 105                 p = argv[0];
 106         else
 107                 ++p;
 108         if (strcmp(p, "unlink") == 0) {
 109                 if (argc == 2) {
 110                         rm_file(&argv[1]);
 111                         exit(eval);
 112                 } else
 113                         usage();
 114         }
 115
 116         Pflag = rflag = 0;
 117         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 118                 switch(ch) {
 119                 case 'd':
 120                         dflag = 1;
 121                         break;
 122                 case 'f':
 123                         fflag = 1;
 124                         iflag = 0;
 125                         break;
 126                 case 'i':
 127                         fflag = 0;
 128                         iflag = 1;
 129                         break;
 130                 case 'P':
 131                         Pflag = 1;
 132                         break;
 133                 case 'R':
 134                 case 'r':                       /* Compatibility. */
 135                         rflag = 1;
 136                         break;
 137                 case 'v':
 138                         vflag = 1;
 139                         break;
 140                 case 'W':
 141                         Wflag = 1;
 142                         break;
 143                 default:
 144                         usage();
 145                 }
 146         argc -= optind;
 147         argv += optind;
 148
 149         if (argc < 1) {
 150                 if (fflag)
 151                         return 0;
 152                 usage();
 153         }
 154
 155         checkdot(argv);
 156         uid = geteuid();
 157
 158         if (*argv) {
 159                 stdin_ok = isatty(STDIN_FILENO);
 160
 161                 if (rflag)
 162                         rm_tree(argv);
 163                 else
 164                         rm_file(argv);
 165         }
 166
 167         exit (eval);
 168 }
 169
 170 void
 171 rm_tree(argv)
 172         char **argv;
 173 {
 174         FTS *fts;
 175         FTSENT *p;
 176         int needstat;
 177         int flags;
 178         int rval;
 179
 180         /*
 181          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 182          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 183          */
 184         needstat = !uid || (!fflag && !iflag && stdin_ok);
 185
 186         /*
 187          * If the -i option is specified, the user can skip on the pre-order
 188          * visit.  The fts_number field flags skipped directories.
 189          */
 190 #define SKIPPED 1
 191
 192         flags = FTS_PHYSICAL;
 193         if (!needstat)
 194                 flags |= FTS_NOSTAT;
 195         if (Wflag)
 196                 flags |= FTS_WHITEOUT;
 197         if (!(fts = fts_open(argv, flags, NULL)))
 198                 err(1, NULL);
 199         while ((p = fts_read(fts)) != NULL) {
 200                 switch (p->fts_info) {
 201                 case FTS_DNR:
 202                         if (!fflag || p->fts_errno != ENOENT) {
 203                                 warnx("%s: %s",
 204                                     p->fts_path, strerror(p->fts_errno));
 205                                 eval = 1;
 206                         }
 207                         continue;
 208                 case FTS_ERR:
 209                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 210                 case FTS_NS:
 211                         /*
 212                          * FTS_NS: assume that if can't stat the file, it
 213                          * can't be unlinked.
 214                          */
 215                         if (!needstat)
 216                                 break;
 217                         if (!fflag || p->fts_errno != ENOENT) {
 218                                 warnx("%s: %s",
 219                                     p->fts_path, strerror(p->fts_errno));
 220                                 eval = 1;
 221                         }
 222                         continue;
 223                 case FTS_D:
 224                         /* Pre-order: give user chance to skip. */
 225                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 226                             p->fts_statp)) {
 227                                 (void)fts_set(fts, p, FTS_SKIP);
 228                                 p->fts_number = SKIPPED;
 229                         }
 230                         else if (!uid &&
 231                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 232                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 233                                  chflags(p->fts_accpath,
 234                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 235                                 goto err;
 236                         continue;
 237                 case FTS_DP:
 238                         /* Post-order: see if user skipped. */
 239                         if (p->fts_number == SKIPPED)
 240                                 continue;
 241                         break;
 242                 default:
 243                         if (!fflag &&
 244                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 245                                 continue;
 246                 }
 247
 248                 rval = 0;
 249                 if (!uid &&
 250                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 251                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 252                         rval = chflags(p->fts_accpath,
 253                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 254                 if (rval == 0) {
 255                         /*
 256                          * If we can't read or search the directory, may still be
 257                          * able to remove it.  Don't print out the un{read,search}able
 258                          * message unless the remove fails.
 259                          */
 260                         switch (p->fts_info) {
 261                         case FTS_DP:
 262                         case FTS_DNR:
 263                                 rval = rmdir(p->fts_accpath);
 264                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 265                                         if (rval == 0 && vflag)
 266                                                 (void)printf("%s\n",
 267                                                     p->fts_path);
 268                                         continue;
 269                                 }
 270                                 break;
 271
 272                         case FTS_W:
 273                                 rval = undelete(p->fts_accpath);
 274                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 275                                         if (vflag)
 276                                                 (void)printf("%s\n",
 277                                                     p->fts_path);
 278                                         continue;
 279                                 }
 280                                 break;
 281
 282                         default:
 283                                 if (Pflag)
 284                                         rm_overwrite(p->fts_accpath, NULL);
 285                                 rval = unlink(p->fts_accpath);
 286                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 287                                         if (rval == 0 && vflag)
 288                                                 (void)printf("%s\n",
 289                                                     p->fts_path);
 290                                         continue;
 291                                 }
 292                         }
 293                 }
 294 err:
 295                 warn("%s", p->fts_path);
 296                 eval = 1;
 297         }
 298         if (errno)
 299                 err(1, "fts_read");
 300 }
 301
 302 void
 303 rm_file(argv)
 304         char **argv;
 305 {
 306         struct stat sb;
 307         int rval;
 308         char *f;
 309
 310         /*
 311          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 312          * to remove a directory is an error, so must always stat the file.
 313          */
 314         while ((f = *argv++) != NULL) {
 315                 /* Assume if can't stat the file, can't unlink it. */
 316                 if (lstat(f, &sb)) {
 317                         if (Wflag) {
 318                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 319                         } else {
 320                                 if (!fflag || errno != ENOENT) {
 321                                         warn("%s", f);
 322                                         eval = 1;
 323                                 }
 324                                 continue;
 325                         }
 326                 } else if (Wflag) {
 327                         warnx("%s: %s", f, strerror(EEXIST));
 328                         eval = 1;
 329                         continue;
 330                 }
 331
 332                 if (S_ISDIR(sb.st_mode) && !dflag) {
 333                         warnx("%s: is a directory", f);
 334                         eval = 1;
 335                         continue;
 336                 }
 337                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 338                         continue;
 339                 rval = 0;
 340                 if (!uid &&
 341                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 342                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 343                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 344                 if (rval == 0) {
 345                         if (S_ISWHT(sb.st_mode))
 346                                 rval = undelete(f);
 347                         else if (S_ISDIR(sb.st_mode))
 348                                 rval = rmdir(f);
 349                         else {
 350                                 if (Pflag)
 351                                         rm_overwrite(f, &sb);
 352                                 rval = unlink(f);
 353                         }
 354                 }
 355                 if (rval && (!fflag || errno != ENOENT)) {
 356                         warn("%s", f);
 357                         eval = 1;
 358                 }
 359                 if (vflag && rval == 0)
 360                         (void)printf("%s\n", f);
 361         }
 362 }
 363
 364 /*
 365  * rm_overwrite --
 366  *      Overwrite the file 3 times with varying bit patterns.
 367  *
 368  * XXX
 369  * This is a cheap way to *really* delete files.  Note that only regular
 370  * files are deleted, directories (and therefore names) will remain.
 371  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 372  * System V file system).  In a logging file system, you'll have to have
 373  * kernel support.
 374  */
 375 void
 376 rm_overwrite(file, sbp)
 377         char *file;
 378         struct stat *sbp;
 379 {
 380         struct stat sb;
 381         struct statfs fsb;
 382         off_t len;
 383         int bsize, fd, wlen;
 384         char *buf = NULL;
 385
 386         fd = -1;
 387         if (sbp == NULL) {
 388                 if (lstat(file, &sb))
 389                         goto err;
 390                 sbp = &sb;
 391         }
 392         if (!S_ISREG(sbp->st_mode))
 393                 return;
 394         if ((fd = open(file, O_WRONLY, 0)) == -1)
 395                 goto err;
 396         if (fstatfs(fd, &fsb) == -1)
 397                 goto err;
 398         bsize = MAX(fsb.f_iosize, 1024);
 399         if ((buf = malloc(bsize)) == NULL)
 400                 err(1, "malloc");
 401
 402 #define PASS(byte) {                                                    \
 403         memset(buf, byte, bsize);                                       \
 404         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 405                 wlen = len < bsize ? len : bsize;                       \
 406                 if (write(fd, buf, wlen) != wlen)                       \
 407                         goto err;                                       \
 408         }                                                               \
 409 }
 410         PASS(0xff);
 411         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 412                 goto err;
 413         PASS(0x00);
 414         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 415                 goto err;
 416         PASS(0xff);
 417         if (!fsync(fd) && !close(fd)) {
 418                 free(buf);
 419                 return;
 420         }
 421
 422 err:    eval = 1;
 423         if (buf)
 424                 free(buf);
 425         warn("%s", file);
 426 }
 427
 428
 429 int
 430 check(path, name, sp)
 431         char *path, *name;
 432         struct stat *sp;
 433 {
 434         int ch, first;
 435         char modep[15], *flagsp;
 436
 437         /* Check -i first. */
 438         if (iflag)
 439                 (void)fprintf(stderr, "remove %s? ", path);
 440         else {
 441                 /*
 442                  * If it's not a symbolic link and it's unwritable and we're
 443                  * talking to a terminal, ask.  Symbolic links are excluded
 444                  * because their permissions are meaningless.  Check stdin_ok
 445                  * first because we may not have stat'ed the file.
 446                  */
 447                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 448                     (!access(name, W_OK) &&
 449                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 450                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 451                         return (1);
 452                 strmode(sp->st_mode, modep);
 453                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 454                         err(1, NULL);
 455                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 456                     modep + 1, modep[9] == ' ' ? "" : " ",
 457                     user_from_uid(sp->st_uid, 0),
 458                     group_from_gid(sp->st_gid, 0),
 459                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 460                     path);
 461 #ifndef __APPLE__
 462                 free(flagsp);
 463 #endif
 464         }
 465         (void)fflush(stderr);
 466
 467         first = ch = getchar();
 468         while (ch != '\n' && ch != EOF)
 469                 ch = getchar();
 470         return (first == 'y' || first == 'Y');
 471 }
 472
 473 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 474 void
 475 checkdot(argv)
 476         char **argv;
 477 {
 478         char *p, **save, **t;
 479         int complained;
 480
 481         complained = 0;
 482         for (t = argv; *t;) {
 483                 if ((p = strrchr(*t, '/')) != NULL)
 484                         ++p;
 485                 else
 486                         p = *t;
 487                 if (ISDOT(p)) {
 488                         if (!complained++)
 489                                 warnx("\".\" and \"..\" may not be removed");
 490                         eval = 1;
 491                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 492                                 continue;
 493                         t = save;
 494                 } else
 495                         ++t;
 496         }
 497 }
 498
 499 void
 500 usage()
 501 {
 502
 503         (void)fprintf(stderr, "%s\n%s\n",
 504             "usage: rm [-f | -i] [-dPRrvW] file ...",
 505             "       unlink file");
 506         exit(EX_USAGE);
 507 }